Maths - Structure

Great site to learn more about Algebra - http://www.mathsisfun.com/algebra/index.html
Algebra balance scales for beginners - http://nlvm.usu.edu/en/nav/frames_asid_324_g_3_t_2.html?open=instructions&from=topic_t_2.html
Algebra tiles - http://nlvm.usu.edu/en/nav/frames_asid_189_g_3_t_2.html?open=activities&from=topic_t_2.html
Function machine - http://nlvm.usu.edu/en/nav/frames_asid_191_g_3_t_2.html?from=topic_t_2.html
Coin problem - http://nlvm.usu.edu/en/nav/frames_asid_139_g_3_t_2.html?from=topic_t_2.html
Peg Puzzle - http://nlvm.usu.edu/en/nav/frames_asid_182_g_3_t_2.html?from=topic_t_2.html
Algebra balance scales - https://www.eduweb.vic.gov.au/dlrcontent/4c33353039/ec_002_utah_008/applet.html
Algebra quiz (more difficult) - http://www.shodor.org/interactivate/activities/AlgebraQuiz/

Cracked Tiles - an intriguing Maths300 problem.